In tool or tool surface resin distribution molding in forming fiber reinforced composite parts, dry fiber composite is laid up on the tool surface forming a preform on the tool surface.
In liquid molding, a fluid impervious sheet, a second tool (with or without grooves) or vacuum bag is then secured to the tool surface over the preform. The edges of the vacuum bag, or tool are sealed to the tool surface to form a sealed volume on the tool surface containing the preform.
A supply of liquid resin is then introduced into the sealed volume to wet the preform on the tool surface. A pressure differential is applied to the sealed volume, to draw the liquid resin across the preform and to infuse the liquid resin into the preform. Vacuum may be applied to create the pressure differential. The liquid resin is then cured, forming the fiber reinforced composite part.
To assist in the distribution of the liquid resin throughout the preform, resin distribution media are often positioned in the sealed volume between the vacuum bag and the tool surface. The resin distribution media is typically positioned on top of the preform and/or beneath the preform. The resin distribution media form pathways through which the liquid resin can flow when infusing the preform with the liquid resin. The resin distribution media thereby distribute the liquid resin entirely over the preform.
However, after curing of the fiber reinforced composite part, the resin distribution media must be removed from the part and discarded. Both the resin distribution media and any additional resin it contains are discarded. Thus, the use of resin distribution media to distribute liquid resin throughout the preform results in wasted resin.
Additionally, as the liquid distribution media is positioned on top of the preform, the fiber composite layup forming the preform can be altered. This could result in a fiber reinforced composite part not having the structural strength intended.
Still further, the use of resin distribution media on the preform to distribute liquid resin throughout the preform could result in the resin distribution media negatively affecting the surface of the fiber reinforced composite part being molded.